The Lee Resolution for independence was passed on July 2 with no opposing votes. The Committee of Five had drafted the Declaration to be ready when Congress voted on independence. John Adams, a leader in pushing for independence, had persuaded the committee to select Thomas Jefferson to compose the original draft of the document, which Congress edited to produce the final version. The Declaration was a formal explanation of why Congress had voted to declare independence from Great Britain, more than a year after the outbreak of the American Revolutionary War. Adams wrote to his wife Abigail, "The Second Day of July 1776, will be the most memorable Epocha, in the History of America" – although Independence Day is actually celebrated on July 4, and states July 4,1776 on the document.

After ratifying the text on July 4, Congress issued the Declaration of Independence in several forms. It was initially published as the printed Dunlap broadside that was widely distributed and read to the public. The source copy used for this printing has been lost and may have been a copy in Thomas Jefferson's hand. Jefferson's original draft is preserved at the Library of Congress, complete with changes made by John Adams and Benjamin Franklin, as well as Jefferson's notes of changes made by Congress. The best-known version of the Declaration is a signed copy that is displayed at the National Archives in Washington, D.C., and which is popularly regarded as the official document.

More Info: en.m.wikipedia.org